Magnesium(II) diaquatetracarbamidenitrate nitrate was structurally studied. Crystals of composition [Mg(H2O)2(ur)4](NO3)2 (I) are monoclinic, Z = 2, P21/n, a = 6.449(1) Å, b = 17.670(2) Å, c = 7.578(1) Å; β = 91.637(2)°. In the structure of complex I, the central magnesium atom has octahedral geometry: the four carbamide molecules are in equatorial positions, and water molecules occupy axial positions.

Eight aluminum, cobalt(II), copper(II), cadmium, samarium(III), and europium(III) complexes with 2,4,6-tris(N,N-dimethylaminomethyl)phenol (HL) were isolated in the crystalline state and studied by physicochemical methods (IR and UV-Vis spectroscopy, potentiometry). The complexation processes of singly, doubly, and triply charged metal ions with HL were studied by spectrophotometry and potentiometry, the composition of complexes was determined, and the stability constants were calculated. The crystal and molecular structures of 2,4,6-tris(N,N-dimethylaminomethyl)phenol trichloride and trinitrate H4L(NO3)3 · H2O and H4LCl3 · 3H2O were studied by X-ray diffraction.

The potassium complex of 2-diphenylacetyl-1,3-indandione (HL), [K(C3H6O)L] (I), was synthesized and studied by X-ray crystallography. Crystals of complex I isolated from chloroform-acetone are monoclinic, Z = 4, space group P21/n, a = 13.293(3) Å, b = 11.246(2) Å, c = 15.050(3) Å, β = 107.91(3)°.

Zinc(II) and manganese(II) complexes of 2-(diphenylacetyl)indandione-1,3 (HL) were synthesized. Crystals of [M(DMSO)2L2] · CHCl3, where M= Zn(II) (I) and Mn(II) (II), obtained from chloroform plus dimethyl sulfoxide (DMSO) mixture were found to be isostructural based on the similarity of their unit cell parameters and unit cell volumes. The crystals are triclinic, Z = 2, space group P \(\bar 1\); a = 10.422(1) Å, b = 11.929(1) Å, c = 20.429(1) Å, α = 73.616(1)°, β = 85.095(1)°, γ = 77.586(1)° for complex I; a = 10.436(1) Å, b = 12.297(1) Å, c = 19.924(2) Å, α = 78.138(2)°, β = 87.625(2)°, γ = 82.048(2)° for complex II. X-ray structural analysis of complex I was carried out. For complex II, the structure was not refined because all of its atoms are each disordered over three to five positions. The two DMSO molecules in complex I coordinate the central metal atoms in the monodentate mode via their donor oxygen atoms to occupy an axial position and an equatorial position in an octahedral polyhedron. The other four positions are occupied by the four oxygen atoms of the two deprotonated ligands L− coordinated in the bidentate-cyclic mode. The outer sphere of complex I contains the solvating chloroform molecule.

Double phosphate Ba1.5Fe2(PO4)3 was synthesized and structurally studied. Single crystals were synthesized by the fusion method. Cubic crystals, Z = 4, space group P213, a = 9.866(1) Å. This structure is built of polyhedrons of four types: PO4 tetrahedrons, two virtually regular FeO6 octahedrons, BaO12 twelve-vertex polyhedrons, and BaO9 nine-vertex polyhedrons. These polyhedrons share common oxygen vertices to form three-dimensional [Fe2(PO4)3]3∞ framework containing barium atoms in cavities.

The crystal structure of a double salt of sodium and cesium with 2-diphenylacetyl-1,3-indandione of the composition [Cs2Na(H2O)2(C23H16O3)(C23H15O3)3] (I) was studied by X-ray crystallography. The crystals of I are monoclinic, Z = 2, space group P21/n, a = 10.212(2) Å, b = 23.479(5) Å, c = 15.638(3) Å, β = 98.30(03)°. The compound contains [Cs2NaO10] trimers, in which the central Na atom shares two edges with two Cs atoms through deprotonated bridging ligands. The trimers are connected to adjacent trimers by paired C-H...O contacts to form layers. The layers form an infinite open framework via hydrogen bonds between the oxygen atoms of keto groups of noncoordinated indandione moieties and water molecules that enter the cesium coordination sphere in trimers of the adjacent layers.

The (HL n ) 2 [CuCl 4 ] complexes (where L n are organic nitrogen-containing bases with n = 1–6) were synthesized. The crystal and molecular structures of bis(2-methylimidazolium) tetrachlorocuprate(II), (HL 1 ) 2 [CuCl 4 ], were determined. The spectral characteristics of the complexes were measured. The correlations between the degree of distortion of the crystal structure of the tetrachlorocuprate anion and the hydrogen bond parameters and the spectral characteristics of compounds were obtained.

Complexes RbL ( I ) and [Li 2 (C 2 H 5 OH)L 2 ] ( II ) (L = C 23 H 15 O 3 ) have been synthesized and their crystal structures have been studied. Both compounds have monoclinic crystals with space group P 2 1 / c and Z = 4; I : a = 11.632(2) Å, b = 15.154(3) Å, c = 11.457(2) Å, β = 104.34(3)°; II : a = 12.982(3)Å, b = 12.083(2) Å, c = 25.317(5) Å β = 100.11(3)°. In the structure of I , dimeric groups [Rb 2 O 6 ] with a shared edge are linked by the ligands to give infinite layers perpendicular to the x axis and cavities that form oblong channels. In the structure of II , Li 2 O 7 dimers are formed by vertex sharing. The coordination of one of the lithium atoms (Li(1)) is completed to tetrahedral by the oxygen atom of the ethanol molecule. The structure of II , like that of I , is layered.

The cationic networks that fix the distribution of cations in planar sections parallel to basis planes of the unit cell of crystal structures have been studied. Topologically identical cationic networks have been shown to be the carriers of deep structure-forming “memory” that successively relates the structures of rare earth metals (La ST) and oxides Ln 2 O 3 ( A -and B -Ln 2 O 3 ST) to the structures of double condensed phosphates MLn(PO 3 ) 4 and MLnP 4 O 12 .

Crystal and molecular structure and spectral characteristics are determined for bis(1-amino-4-azafluoren-9-olium) and bis(2-amino-3-hydroxypyridinium) tetrachlorocobaltates(II): CoCl4(C12H11N2O)2 and CoCl4(C5H7N2O)2, respectively. The structural units of the complexes are CoCl 4 2− anions and organic cations protonated at the pyridine nitrogen atom.

Single crystals of the solid solutions CdGeAs2:Mn(x) and Cd0.964Zn0.036GeAs2:Mn(x) have been grown by the vertical Bridgman method. An X-ray diffraction study has demonstrated that Cd0.964Zn0.036GeAs2 (I), Cd0.964Zn0.036GeAs2:Mn (1.5 wt%) (II), and Cd0.964Zn0.036GeAs2:Mn (2.18 wt %) (III) retain the CdGeAs2 structure (tetragonal system, space group I \(\bar 4\)2d). The unit cell parameters of the solid solutions are as follows: a = b = 5.934(1) Å, c = 11.219(2) Å for I; a = b = 5.919(1) Å, c = 11.204(2) Å for II; and a = b = 5.918(1) Å, c = 11.208(2) Å for III. Many of Mn atoms in II and III occupy interstitial sites in the crystal lattice. Selected electrical and magnetic properties of single crystals of CdGeAs2:Mn(x) are discussed.

Crystals of double polyphosphates EuCs 5 (PO 3 ) 8 ( I ) and GdCs 5 (PO 3 ) 8 ( II ) have been studied by X-ray diffraction. The isostructural crystals of I and II are monoclinic, space group C 2. Only unit cell parameters have been determined for the crystals of double Pr and Cs polyphosphate ( III ). This crystal is isostructural with earlier studied La 3 Cs 15 P 24 O 72 · 6H 2 O ( IV ). The crystals of compounds III and IV are triclinic, space group P 1, Z = 1; a = 11.987(2) and 12.178(5) Å, b = 14.754(8) and 14.740(8) Å, c = 14.692(8) and 14.847(9) Å, α = 60.15(4)° and 60.87(5)°, β = 67.04(4)° and 66.35(4)°, γ = 78.76(3)° and 77.54(4)°, respectively. In compounds I and II , the polyphosphate anions exist as infinite chains. The M III O 8 polyhedra are isolated from each other but share edges and faces with the CsO n polyhedra.

Complexes of copper(II) halides (chlorides and bromides) with some 4-azafluorene derivatives have been synthesized and studied by X-ray crystallography and IR and UV spectroscopy. In neutral media, Cu(L)2X2 (X = Cl, Br) complexes are formed in which the ligands are coordinated to the metal atoms though the lone pair of the endocyclic nitrogen atom and through the oxygen atoms of substituents. In acid media at pH 2, (HL2)2CuX4 complexes are formed in which the 4-azafluorene molecules protonated at the endocyclic nitrogen atom act as an outer-sphere cation. The molecule and crystal structure of 4-aza-9-oxofluorenium tetrabromocuprate hydrate (HL4)2CuBr4·H2O has been determined.

High-quality ZnSnAs 2 (I) single crystals have been grown. The unit cell parameters of compound I have been refined ( a = b = 5.8360(1), c = 11.686(2) Å), and its crystal structure has been determined.

An Ag(I) complex with HL ( I ), AgL (AgC 23 H 15 O 3 , II ), has been synthesized. Compounds I and II have been studied by X-ray diffraction. The crystals are monoclinic, I : space group P 2 1 / n , a = 10.459(2) Å, b = 12.354(2) Å, c = 13.390(3) Å, β = 96.67(3)°, Z = 4; II : space group P 2 1 / c , a = 10.764(2) Å, b = 10.683(2) Å, c = 15.939(3) Å, β = 101.57(3)°, Z = 4. The structural units of the crystal of I are neutral molecules with intramolecular hydrogen bonds. In structure II , the Ag 2 O 6 dimeric groups and the ligands form infinite openwork layers perpendicular to the x axis and containing cavities. The layers are penetrated by channels with an oblong cross section. In the crystal of II , all intermolecular distances exceed the sums of the van der Waals radii of the corresponding atoms.

Specific features of the textures (the preferred orientation of the nanometer building blocks) of the cationic and anionic components of the structures of phosphates forming in the Ln 2 O 3 -P 2 O 5 systems (Ln = Er-Lu) have been studied. Nanostructuring upon the formation of phosphates is determined by two oppositely directed processes of fragmentation of corresponding infinite cationic and anionic frameworks to elementary blocks, LnO n polyhedra and [PO 4 ] tetrahedra.

Specific features of the textures (the preferred orientation of the nanometer building blocks) in the structures of mixed-anion compounds—rare-earth borogermanates, germanophosphates, and borotungstates that arise from the acid-base interaction in the Ln 2 O 3 -B 2 O 3 -GeO 2 , Ln 2 O 3 -GeO 2 -P 2 O 5 , and Ln 2 O 3 -B 2 O 3 -WO 3 systems (Ln = La-Gd)—have been studied. Based on characteristic texture traits, the mixed-anion compounds of early rare-earth elements can be divided into three groups: (i) Ln 2 O 3 : E x O y > 1, (ii) Ln 2 O 3 : E x O y = 1, and (iii) Ln 2 O 3 : E x O y < 1. Because of the dominant structural effect of the basic oxide Ln 2 O 3 in the compounds of the first group, the structures of Nd 14 O 8 (BO 3 ) 6 (GeO 4 ) 2 and Pr 11 O 10 (GeO 4 )(PO 4 ) 3 are composed of infinite [LnO n ] bands and layers and discrete groups [EO m ] located in the interband and interlayer spaces. The dominant structural effect of the acid oxides [E x O y ] in the compounds of the third group leads to the appearance of ring textures composed of [LnO n ], as well as to the appearance of chains and networks composed of [EO m ], in the structures of Ln(BGeO 5 ) and Ln(BO 2 )(WO 4 ).

The initial stages of the formation of CdAs2-ZnAs2 solid solutions are analyzed in terms of crystalchemical energetics. Given that the bond enthalpies decrease in the order H (Zn-As)< H (Cd-As)< H (As-As), it is concluded that, most likely, CdAs2-based solid solutions are substitutional and ZnAs2-based solid solutions are interstitial, and that the thermochemical stability of the substitutional solid solutions is higher than that of CdAs2 . The conclusions drawn from crystal-chemical analysis correlate with the reported x-ray diffraction, chemical analysis, resistivity, and Hall data for the solid solutions.

Large, perfect CdGeAs2 single crystals doped with 0.006, 0.49, and 0.89 wt % Mn are grown by the Bridgman method. The Mn concentration in the crystals is determined by atomic absorption spectrophotometry. X-ray diffraction results indicate that Mn doping influences the bond distances in CdGeAs2 and its lattice parameters. Based on the observed structural changes, a model is proposed for the Mn incorporation into the structure of CdGeAs2.